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Re: [Xen-devel] arp during live migration

To: "Graham, Simon" <Simon.Graham@xxxxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] arp during live migration
From: Keir Fraser <keir@xxxxxxxxxxxxx>
Date: Wed, 07 Mar 2007 16:02:02 +0000
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On 6/3/07 22:59, "Graham, Simon" <Simon.Graham@xxxxxxxxxxx> wrote:

> All of this leads to a ~1s delay setting up the network path plus the
> gratuitous ARP is dropped so there can be a MUCH larger network
> blackout. If you are trying to get sub-second blackout on migration this
> is a big problem!
> It seems to me that the right thing to do here is to have the link up on
> the VIF in advance of the domain resuming on the target but I'm guessing
> that this would cause netback to have conniptions...

Changeset 14280 in xen-unstable fixes this by no longer using the
netif_carrier flag. The patch will probably backport very straightforwardly
onto older (or newer) 2.6 Linux kernels.

 -- Keir

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